Thus, Makefile must contain the check-syntax target. In
our case this target might look like this:

check-syntax:
gcc -o /dev/null -S ${CHK_SOURCES}

The format of error messages reported by gcc is already
supported by Flymake, so we don't have to add a new entry to
flymake-err-line-patterns. Note that if you are using
Automake, you may want to replace gcc with the standard
Automake variable COMPILE: